Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2016

Quarterly results of operations for the years ended December 31, 2016 and 2015 are summarized below:



	Three Months Ended
	March 31		June 30		September 30		December 31
	(in thousands, except per share amounts)
2016
Operating revenue	$	538,143	$	584,133	$	621,329	$	578,351
Operating income	101,299		121,835		135,216		85,311
Net income	61,920		73,084		81,382		48,493
Basic earnings per share	0.87		1.03		1.17		0.70
Diluted earnings per share	0.86		1.03		1.17		0.70

2015
Operating revenue	$	493,355	$	553,421	$	574,841	$	519,846
Operating income	109,251		122,315		157,219		120,337
Net income	69,002		76,704		97,114		74,400
Basic earnings per share	0.94		1.06		1.35		1.04
Diluted earnings per share	0.94		1.05		1.35		1.04